Electric gas or vapor lamp and electrode therefor.



Patented Sept. l7, 190k Inventor P. c. HEWITT. ELECTRIC GAS 0R VAPORLAMP AND ELECTRODE THEREFOR.

(Application filed. Apr. 5, 1900.)

(No Model.)

NITED STATES PATENT QFFICE.

PETER COOPER HEWITT, OF NEW YQRK, N. Y., ASSIGNOR TO PETER COOPERHEWITT, TRUSTEE, OF SAME PLACE.

ELECTRIC GAS OR VAPOR LAMP AND. ELECTRODE THEREFOR.

SPECIFICATION forming part of Letters Patent No. 682,694, datedSeptember 17, 1901.

Application filed April 5, 1900. Serial No. 11,616. (No model.)

To all whom it may concern:

Be it known that 1, PETER OooPER HEWITT, a citizen of the United States,and a resident of New York, in the county of New York and State of NewYork, have invented certain new and useful Improvements in Electric Gasor Vapor Lamps and Electrodes Therefor, of which the following is aspecification. My invention relates to that class of electric-lightingdevices in which electric energy is transformed into light by its actionupon gases or vapors inclosed in a suitable chamber.

In the operation of lamps of the character referred to I have found thatsuitable gases having the proper density may be so affected by electriccurrents of moderate electromotive force as to yield an intense lightand operate at very high efficiencies. he resistance which a lamp ofthis character offers to the passage of current seems to reside in thegas carrying the current between the electrodes and at-the point betweenthe gas or vapor and the electrodes,- particularly the cathode. When thelamp is started and receives current, these resistances may be soadjusted as to cause the lamp to be self-regulating. In operating thelamps the electric current tends to pass around to the back of theoathode, and unless prevented is liable to fuse the leading-inconductors and disintegrate the glass usually surrounding them. To avoidthis I provide an electrically-tight protecting-covering for suchportions of the electrode, leaving exposed only those portions at whichit is desired that the current shall enter. This phenomenon mainlymanifests itself at the negative electrode.

The accompanying drawing illustrates a lamp having electrodes embodyingmy-invention.

Referring to the drawing, l'represents the main body of the lamp.

2 represents an electrode (in this instance assumed to be the anode)located in the upper part of the lamp and within or near the neck of anenlargement 4, which is sometimes employed as a coolingrchamber. ode isrepresented at 5. These electrodes may be made of suitable metalsuch,for instance, as iron or any desired conducting ma- The oath terial. Theelectrode 2'is shown as being seated within a porcelain sleeve 11, whichis held by a glass column 10, surrounding the leading-in wire '7. Theelectrode 5 is shown as being seated within a tube 14, of porcelain orother suitable material which is a non-conductor at such temperatures asit may attain in the lamp and inert to chemical reactions at thetemperatures and surroundings to which itis subjected in the operationof the lamp. The cylinder 14 is shown as being car ried by the stem orcolumn 12 of glass, through which the leading-in wire 8 is passed. The

joints between the electrode and the porce= lain and between theporcelain and the glass are suificiently tight to prevent the electriccurrent from passing through them, and thus reaching the metal partswithin, thus making a complete insulation of the stem of the elec- 7otrode from the wall of the vessel to the electrode.

With electrodes of the character described I am able to operate the lampso that the current will pass to and from the electrodes and beprevented from passing around to the portions near the leading-in wires.

In the operation of lamps of this character it is possible for thecurrent to heat the oathode to a very high temperature and yet notimpair the non-conducting quality of the material protecting theconductor leading to it.

In certain other applications filed by mefor instance, Serial Nos.11,605, 11,606, and 11,607, filed April 5, 1900, and Serial Nos. 44,647,44,648, and 44,649, filed January 25', 190l-claims are made upon certainof the features disclosed herein.

The invention claimed is 1. The combination of a closed chamber, a 0

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3. In a gas or vapor lamp, an electrode having an exposedconducting-surface, a sleeve or covering of insulating materialprotecting the remaining portion of the electrode, and a non-conductingsupporting-pillar for the sleeve composed of a different materialtherefrom.

4:. In an electric lamp having a vapor or gas path of such density as toconduct currents, an electrode having an exposed portion, anon-conductor surrounding the conductor leading to the electrode forprotecting said conductor, consisting of a material inert to chemicalreactions Within the lamp and forming an electrically-tight jointtherewith.

5. The combination of a closed chamber, a

PETER COOPER HEWITT.

Witnesses:

WM. l-I. CAPEL, CHARLES B. HILL.

